This invention relates to the packaging art and has particular reference to an improved carton for packaging fragile articles, such as electric lamps, and to the improved package which results from the use of such a carton.
In order to protect the glass envelopes of electric lamps from breakage during shipment and when being displayed and handled at the retail level, the lamps are customarily placed in a suitable wrapper or carton at the lamp factory. Due to the large numbers of electric lamps that are manufactured and marketed each year, the cost of packaging material is an important factor in the lamp industry. To minimize such costs, the electric lamps are packaged by slipping them into wrappers or cartons of open-ended tubular configuration that are made of suitable packaging material such as paperboard. Further reductions in material cost were achieved in the prior art by making the tubular containers of hexagonal rather than square cross-section and providing them with inturned article-retaining or rigidifying flaps. A fiberboard container of hexagonal configuration having a series of inturned panels that are formed from parts of the container walls and thus provide means for rigidifying the container and supporting an inserted article such as a light bulb is disclosed in U.S. Pat. No. 3,750,934 issued Aug. 7, 1973 to Clinage. An open-ended carton of square cross-section for packaging a parabolic lamp bulb and having a pair of yoke-like platforms formed by inturned against flaps that are cut from the carton walls and support and display the inserted lamp is disclosed in U.S. Pat. No. 3,734,397 issued May 22, 1973 to Cote.
A dispensing-type carton that is of octagonal configuration and has flap elements which provide a snap-action self-locking end closure for the carton is disclosed in U.S. Pat. No. 3,526,352 issued Sept. 1, 1970 to Swett. A self-locking paperboard container comprising a tubular body portion of octagonal configuration having a cap member of the same configuration is disclosed in U.S. Pat. No. 4,134,531 issued Jan. 16, 1979 to Martinez et al.
While the prior art containers and cartons were generally satisfactory from the standpoint of providing integral locking or rigidifying means which retained the loaded lamp or other article within the carton and provided display openings, they were so constructed that they were difficult to set up for loading and thus did not meet the stringent labor-efficiency standards required for the mass-production of electric lamps and similar articles. The present invention solves this problem by providing a carton which can be easily and quickly set up for loading and then automatically locked in such condition by an integral flap assembly that not only conserves packaging material but attractively exposes selected portions of the packaged lamp (or other article) to the view of perspective purchasers.
In accordance with a preferred embodiment, the foregoing advantages are obtained by fabricating the carton from a single piece of boxboard or the like that is cut, scored and glued together in such a fashion that the carton collapses flat for bulk shipment to the lamp factory and, when expanded, forms an open-ended hexagonal sleeve that is automatically locked in such configuration by an internal platform that is actuated and snapped into place by the pivotal forces created during the setting-up operation. This very advantageous automatic self-locking feature is achieved by utilizing parts of opposing walls of the carton to form the platform and by so gluing and scoring such parts that they comprise a foldable integral flap assembly that snapes into "platform-forming" position by means of a toggle-like joint just as the carton reaches its fully-expanded tubular configuration. The various panels which comprise the foldable flap assembly are so oriented and shaped that they leave window-openings in the sides of the erected carton through which the electric lamp (or other article) inserted into the carbon can be seen. Cutouts provided in selected panels of the foldable flap assembly automatically align with one another when the assembly snaps into its platform configuration and form a central aperture in the platform which is dimensioned to frictionally engage the based-end portion of the inserted electric lamp.
The unique platform-forming flap assembly of the present invention accordingly not only conserves packaging material and greatly facilitates the setting-up and loading of the carton but securely holds the inserted lamp in its loaded position within the carton and provides side windows for attractively displaying the packaged lamp to prospective purchasers.